scholarly journals Leaf nitrogen from first principles: field evidence for adaptive variation with climate

2016 ◽  
Author(s):  
Ning Dong ◽  
Iain Colin Prentice ◽  
Bradley J. Evans ◽  
Stefan Caddy-Retalic ◽  
Andrew J. Lowe ◽  
...  
Keyword(s):  
Environmental Gradients ◽  
Species Turnover ◽  
Leaf Nitrogen ◽  
Functional Ecology ◽  
Leaf Mass Per Area ◽  
Mean Annual Temperature ◽  
Rubisco Activity ◽  
Trait Variation ◽  
Leaf Trait ◽  
Field Evidence

Abstract. Nitrogen content per unit leaf area (Narea) is a key variable in plant functional ecology and biogeochemistry. Narea comprises a structural component, which scales with leaf mass per area (LMA), and a metabolic component, which scales with Rubisco capacity. The co-ordination hypothesis, as implemented in LPJ and related global vegetation models, predicts that Rubisco capacity should be directly proportional to irradiance but should decrease with ci:ca and temperature because the amount of Rubisco required to achieve a given assimilation rate declines with both. We tested these predictions using LMA, leaf δ13C and leaf N measurements on complete species assemblages sampled at sites on a North-South transect from tropical to temperate Australia. Partial effects of mean canopy irradiance, mean annual temperature and ci:ca (from δ13C) on Narea were all significant and their directions and magnitudes were in line with predictions. Over 80 % of the variance in community-mean (ln) Narea was accounted for by these predictors plus LMA. Moreover, Narea could be decomposed into two components, one proportional to LMA (slightly steeper in N-fixers), the other to predicted Rubisco activity. Trait gradient analysis revealed ci:ca to be perfectly plastic, while species turnover contributed about half the variation in LMA and Narea. Interest has surged in methods to predict continuous leaf-trait variation from environmental factors, in order to improve ecosystem models. Our results indicate that Narea has a useful degree of predictability, from a combination of LMA and ci:ca – themselves in part environmentally determined – with Rubisco activity, as predicted from local growing conditions. This is consistent with a 'plant-centred' approach to modelling, emphasizing the adaptive regulation of traits. Models that account for biodiversity will also need to partition community-level trait variation into components due to phenotypic plasticity and/or genotypic differentiation within species, versus progressive species replacement, along environmental gradients. Our analysis suggests that variation in Narea is about evenly split between these two modes.

scholarly journals Leaf nitrogen from first principles: field evidence for adaptive variation with climate

2017 ◽  
Vol 14 (2) ◽  
pp. 481-495 ◽  
Author(s):  
Ning Dong ◽  
Iain Colin Prentice ◽  
Bradley J. Evans ◽  
Stefan Caddy-Retalic ◽  
Andrew J. Lowe ◽  
...  
Keyword(s):  
Photosynthetic Capacity ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Leaf Nitrogen ◽  
Functional Ecology ◽  
Leaf Mass Per Area ◽  
Mean Annual Temperature ◽  
Trait Variation ◽  
Leaf Trait ◽  
Field Evidence

Abstract. Nitrogen content per unit leaf area (Narea) is a key variable in plant functional ecology and biogeochemistry. Narea comprises a structural component, which scales with leaf mass per area (LMA), and a metabolic component, which scales with Rubisco capacity. The co-ordination hypothesis, as implemented in LPJ and related global vegetation models, predicts that Rubisco capacity should be directly proportional to irradiance but should decrease with increases in ci : ca and temperature because the amount of Rubisco required to achieve a given assimilation rate declines with increases in both. We tested these predictions using LMA, leaf δ13C, and leaf N measurements on complete species assemblages sampled at sites on a north–south transect from tropical to temperate Australia. Partial effects of mean canopy irradiance, mean annual temperature, and ci : ca (from δ13C) on Narea were all significant and their directions and magnitudes were in line with predictions. Over 80 % of the variance in community-mean (ln) Narea was accounted for by these predictors plus LMA. Moreover, Narea could be decomposed into two components, one proportional to LMA (slightly steeper in N-fixers), and the other to Rubisco capacity as predicted by the co-ordination hypothesis. Trait gradient analysis revealed ci : ca to be perfectly plastic, while species turnover contributed about half the variation in LMA and Narea. Interest has surged in methods to predict continuous leaf-trait variation from environmental factors, in order to improve ecosystem models. Coupled carbon–nitrogen models require a method to predict Narea that is more realistic than the widespread assumptions that Narea is proportional to photosynthetic capacity, and/or that Narea (and photosynthetic capacity) are determined by N supply from the soil. Our results indicate that Narea has a useful degree of predictability, from a combination of LMA and ci : ca – themselves in part environmentally determined – with Rubisco activity, as predicted from local growing conditions. This finding is consistent with a plant-centred approach to modelling, emphasizing the adaptive regulation of traits. Models that account for biodiversity will also need to partition community-level trait variation into components due to phenotypic plasticity and/or genotypic differentiation within species vs. progressive species replacement, along environmental gradients. Our analysis suggests that variation in Narea is about evenly split between these two modes.

scholarly journals Intraspecific trait variability and community assembly in hawkmoths (Lepidoptera: Sphingidae) across an elevational gradient in the eastern Himalayas, India

2019 ◽  
Author(s):  
Mansi Mungee ◽  
Ramana Athreya
Keyword(s):  
Community Assembly ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Elevational Gradient ◽  
Functional Ecology ◽  
List Type ◽  
Environmental Response ◽  
Trait Variation ◽  
Eastern Himalayas ◽  
Response Traits

AbstractRecent progress in functional ecology has advanced our understanding of the role of intraspecific (ITV) and interspecific (STV) trait variation in community assembly across environmental gradients. Studies on plant communities have generally found STV as the main driver of community trait variation, whereas ITV plays an important role in determining species co-existence and community assembly. However, similar studies of faunal taxa, especially invertebrates, are very few in number.We investigated variation of hawkmoth (Lepidoptera: Sphingidae) traits along an environmental gradient spanning 2600 m in the eastern Himalayas and its role in community assembly, using the morpho-functional traits of body mass (BM), wing loading (WL) and wing aspect ratio (AR).We employ the recently proposed T-statistics to test for non-random assembly of hawkmoth communities and the relative importance of the two opposing forces for trait divergence (internal filters) and convergence (external filters).Community-wide trait-overlap decreased for all three traits with increasing environmental distance, suggesting the presence of elevation specific optimum morphology (i.e. functional response traits). Community weighted mean of BM and AR increased with elevation. Overall, the variation was dominated by species turnover but ITV accounted for 25%, 23% and <1% variability of BM, WL and AR, respectively. T-statistics, which incorporates ITV, revealed that elevational communities had a non-random trait distribution, and that community assembly was dominated by internal filtering throughout the gradient.This study was carried out using easily measurable morpho-traits obtained from calibrated field images of a large number (3301) of individuals. That these also happened to be important environmental response traits resulted in a significant signal in the metrics that we investigated. Such studies of abundant and hyperdiverse invertebrate groups across large environmental gradients should considerably improve our understanding of community assembly processes.

Within-species leaf trait variation and ecological flexibility in resprouting tropical trees

2012 ◽  
Vol 28 (5) ◽  
pp. 527-530 ◽  
Author(s):  
Carl F. Salk
Keyword(s):  
Leaf Area ◽  
Tree Species ◽  
Environmental Changes ◽  
Functional Trait ◽  
Leaf Mass Per Area ◽  
Trait Variation ◽  
Leaf Functional Traits ◽  
Leaf Trait ◽  
Neotropical Tree ◽  
Ecological Flexibility

Plants have an inherent flexibility to respond to different environmental conditions. One axis of plant ecophysiological strategy is seen in the spectrum of leaf functional traits. Flexibility in these traits would be suggestive of plants’ phenotypic plasticity in response to environmental changes. This research seeks to identify differences between leaves of sprout and non-sprout shoots of a broad ecological range of neotropical tree species. Using a functional-trait approach, this study assesses a large pool of species for within-species physiological flexibility. Leaf mass per area (LMA) and leaf area were measured for plants of sprout and non-sprout origin for 26 tree species grown in a reforestation plantation in Panama. Sprouts had a consistently lower LMA than non-sprouts, but there was no consistent pattern for leaf area. These trends show that sprouts are more like pioneer species than conspecific saplings, a finding in general agreement with fast sprout growth seen in previous studies. Further, later-successional (high LMA) species showed a greater reduction of LMA in sprouts. These results show that tropical tree species adjust physiologically to changing ecological roles and suggest that certain species may be more resilient than realized to changing climate and disturbance patterns.

scholarly journals Distinct Responses of Leaf Traits to Environment and Phylogeny Between Herbaceous and Woody Angiosperm Species in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Nannan An ◽  
Nan Lu ◽  
Bojie Fu ◽  
Mengyu Wang ◽  
Nianpeng He
Keyword(s):  
Leaf Area ◽  
Woody Species ◽  
Leaf Traits ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Dry Matter Content ◽  
Trait Variation ◽  
Leaf Trait ◽  
Environment Variables ◽  
Angiosperm Species

Leaf traits play key roles in plant resource acquisition and ecosystem processes; however, whether the effects of environment and phylogeny on leaf traits differ between herbaceous and woody species remains unclear. To address this, in this study, we collected data for five key leaf traits from 1,819 angiosperm species across 530 sites in China. The leaf traits included specific leaf area, leaf dry matter content, leaf area, leaf N concentration, and leaf P concentration, all of which are closely related to trade-offs between resource uptake and leaf construction. We quantified the relative contributions of environment variables and phylogeny to leaf trait variation for all species, as well as for herbaceous and woody species separately. We found that environmental factors explained most of the variation (44.4–65.5%) in leaf traits (compared with 3.9–23.3% for phylogeny). Climate variability and seasonality variables, in particular, mean temperature of the warmest and coldest seasons of a year (MTWM/MTWQ and MTCM/MTCQ) and mean precipitation in the wettest and driest seasons of a year (MPWM/MPWQ and MPDM/MPDQ), were more important drivers of leaf trait variation than mean annual temperature (MAT) and mean annual precipitation (MAP). Furthermore, the responses of leaf traits to environment variables and phylogeny differed between herbaceous and woody species. Our study demonstrated the different effects of environment variables and phylogeny on leaf traits among different plant growth forms, which is expected to advance the understanding of plant adaptive strategies and trait evolution under different environmental conditions.

scholarly journals Leaf trait variation in species-rich tropical Andean forests

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jürgen Homeier ◽  
Tabea Seeler ◽  
Kerstin Pierick ◽  
Christoph Leuschner
Keyword(s):  
Environmental Gradients ◽  
Elevation Gradient ◽  
Environmental Filtering ◽  
Leaf Thickness ◽  
Community Level ◽  
Plant Performance ◽  
Small Scale ◽  
Trait Variation ◽  
Leaf Trait ◽  
Foliar N

AbstractScreening species-rich communities for the variation in functional traits along environmental gradients may help understanding the abiotic drivers of plant performance in a mechanistic way. We investigated tree leaf trait variation along an elevation gradient (1000–3000 m) in highly diverse neotropical montane forests to test the hypothesis that elevational trait change reflects a trend toward more conservative resource use strategies at higher elevations, with interspecific trait variation decreasing and trait integration increasing due to environmental filtering. Analysis of trait variance partitioning across the 52 tree species revealed for most traits a dominant influence of phylogeny, except for SLA, leaf thickness and foliar Ca, where elevation was most influential. The community-level means of SLA, foliar N and Ca, and foliar N/P ratio decreased with elevation, while leaf thickness and toughness increased. The contribution of intraspecific variation was substantial at the community level in most traits, yet smaller than the interspecific component. Both within-species and between-species trait variation did not change systematically with elevation. High phylogenetic diversity, together with small-scale edaphic heterogeneity, cause large interspecific leaf trait variation in these hyper-diverse Andean forests. Trait network analysis revealed increasing leaf trait integration with elevation, suggesting stronger environmental filtering at colder and nutrient-poorer sites.

Short Communication: Leaf trait relationships in Australian plant species

2004 ◽  
Vol 31 (5) ◽  
pp. 551 ◽  
Author(s):  
Ian J. Wright ◽  
Philip K. Groom ◽  
Byron B. Lamont ◽  
Pieter Poot ◽  
Lynda D. Prior ◽  
...  
Keyword(s):  
Plant Species ◽  
Dark Respiration ◽  
Leaf Nitrogen ◽  
Low Fertility ◽  
Trait Variation ◽  
Leaf Trait ◽  
Woody Perennials ◽  
Australian Plant ◽  
Global Datasets ◽  
Broad Scale

Leaf trait data were compiled for 258 Australian plant species from several habitat types dominated by woody perennials. Specific leaf area (SLA), photosynthetic capacity, dark respiration rate and leaf nitrogen (N) and phosphorus (P) concentrations were positively correlated with one another and negatively correlated with average leaf lifespan. These trait relationships were consistent with previous results from global datasets. Together, these traits form a spectrum of variation running from species with cheap but frequently replaced leaves to those with strategies more attuned to a nutrient-conserving lifestyle. Australian species tended to have SLAs at the lower end of the spectrum, as expected in a dataset dominated by sclerophyllous species from low fertility or low rainfall sites. The existence of broad-scale, 'global' relationships does not imply that the same trait relationships will always be observed in small datasets. In particular, the probability of observing concordant patterns depends on the range of trait variation in a dataset, which, itself, may vary with sample size or species-sampling properties such as the range of growth forms, plant functional 'types', or taxa included in a particular study. The considerable scatter seen in these broad-scale trait relationships may be associated with climate, physiology and phylogeny.

scholarly journals Intraspecific variation shapes community-level behavioural responses to urbanisation in spiders: from traits to function

2016 ◽  
Author(s):  
Maxime Dahirel ◽  
Jasper Dierick ◽  
Maarten De Cock ◽  
Bonte Dries
Keyword(s):  
Ecosystem Functioning ◽  
Urban Areas ◽  
Environmental Changes ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Community Level ◽  
List Type ◽  
Trait Variation ◽  
Behavioural Responses ◽  
Intraspecific Trait Variation

SummaryApproaches based on functional traits have proven especially valuable to understand how communities respond to environmental gradients. Until recently, they have, however, often ignored the potential consequences of intraspecific trait variation (ITV). This position becomes potentially more problematic when studying animals and behavioural traits, as behaviours can be altered very flexibly at the individual level to track environmental changes.Urban areas are an extreme example of human-changed environments, exposing organisms to multiple, strong, yet relatively standardized, selection pressures. Adaptive behavioural responses are thought to play a major role in animals’ success or failure in these new environments. The consequences of such behavioural changes for ecosystem processes remain understudied.Using 62 sites of varying urbanisation level, we investigated how species turnover and ITV influenced community-level behavioural responses to urbanisation, using orb web spiders and their webs as models of foraging behaviour.ITV explained around 30% of the total trait variation observed among communities. Spiders altered their web-building behaviour in cities in ways that increase the capture efficiency of webs. These traits shifts were partly mediated by species turnover, but ITV increased their magnitude. The importance of ITV varied depending on traits and on the spatial scale at which urbanisation was considered. Available prey biomass decreased with urbanisation; the corresponding decrease in prey interception by spiders was less important when ITV in web traits was accounted for.By facilitating trait-environment matching despite urbanisation, ITV thus helps communities to buffer the effects of environmental changes on ecosystem functioning. Despite being often neglected from community-level analyses, our results highlight the importance of accounting for intraspecific trait variation to fully understand trait responses to (human-induced) environmental changes and their impact on ecosystem functioning.

scholarly journals Components of leaf‐trait variation along environmental gradients

2020 ◽  
Vol 228 (1) ◽  
pp. 82-94 ◽  
Author(s):  
Ning Dong ◽  
Iain Colin Prentice ◽  
Ian J. Wright ◽  
Bradley J. Evans ◽  
Henrique F. Togashi ◽  
...  
Keyword(s):  
Environmental Gradients ◽  
Trait Variation ◽  
Leaf Trait

scholarly journals Basin-wide variations in foliar properties of Amazonian forest: phylogeny, soils and climate

2009 ◽  
Vol 6 (2) ◽  
pp. 3707-3769 ◽  
Author(s):  
N. M. Fyllas ◽  
S. Patiño ◽  
T. R. Baker ◽  
G. Bielefeld Nardoto ◽  
L. A. Martinelli ◽  
...  
Keyword(s):  
Tree Species ◽  
Nutrient Concentrations ◽  
Leaf Mass Per Area ◽  
Mean Annual Temperature ◽  
High Fertility ◽  
Trait Variation ◽  
Growth Environment ◽  
Precipitation Regimes ◽  
Wide Range ◽  
Leaf Level

Abstract. We analysed 1040 individual trees, positioned in sixty three plots across the Amazon Basin for leaf mass per area (MA), leaf carbon isotope composition (δ13C) and leaf level concentrations of C, N, P, Ca, Mg, K and Al. All trees were identified to the species with the dataset containing 58 families, 236 genera and 508 species, distributed across a wide range of soil types and precipitation regimes. Some foliar characters such as MA, [C], [N] and [Mg] emerge as highly constrained by the taxonomic affiliation of tree species, but with others such as [P], [K], [Ca] and δ13C also strongly influenced by site growing conditions. By removing the environmental contribution to trait variation, we find that intrinsic values of most trait pairs coordinate, although different species (characterised by different trait suites) are found at discrete locations along a common axis of coordination. Species that tend to occupy higher fertility soils are characterised by a lower MA and have a higher intrinsic [N], [P], [K], [Mg] and δ13C than their lower fertility counterparts. Despite this consistency, different scaling patterns were observed between low and high fertility sites. Inter-relationships are thus substantially modified by growth environment. Analysing the environmental component of trait variation, we found soil fertility to be the most important predictor, influencing all leaf nutrient concentrations and δ13C composition and reducing MA. Mean annual temperature was negatively associated with leaf level [N], [P] and [K] concentrations. Total annual precipitation positively influences MA, [C] and δ13C, but with a negative impact on [Mg]. These results provide a first basis for understanding the relationship between the physiological functioning and distribution of tree species across Amazonia.

scholarly journals Responses of leaf traits to climatic gradients: adaptive variation versus compositional shifts

2015 ◽  
Vol 12 (18) ◽  
pp. 5339-5352 ◽  
Author(s):  
T.-T. Meng ◽  
H. Wang ◽  
S. P. Harrison ◽  
I. C. Prentice ◽  
J. Ni ◽  
...  
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Linear Models ◽  
Environmental Gradients ◽  
Empirical Studies ◽  
Matter Content ◽  
Dry Matter Content ◽  
Adaptive Variation ◽  
Trait Variation ◽  
Leaf Trait

Abstract. Dynamic global vegetation models (DGVMs) typically rely on plant functional types (PFTs), which are assigned distinct environmental tolerances and replace one another progressively along environmental gradients. Fixed values of traits are assigned to each PFT; modelled trait variation along gradients is thus driven by PFT replacement. But empirical studies have revealed "universal" scaling relationships (quantitative trait variations with climate that are similar within and between species, PFTs and communities); and continuous, adaptive trait variation has been proposed to replace PFTs as the basis for next-generation DGVMs. Here we analyse quantitative leaf-trait variation on long temperature and moisture gradients in China with a view to understanding the relative importance of PFT replacement vs. continuous adaptive variation within PFTs. Leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC) and nitrogen content of dry matter were measured on all species at 80 sites ranging from temperate to tropical climates and from dense forests to deserts. Chlorophyll fluorescence traits and carbon, phosphorus and potassium contents were measured at 47 sites. Generalized linear models were used to relate log-transformed trait values to growing-season temperature and moisture indices, with or without PFT identity as a predictor, and to test for differences in trait responses among PFTs. Continuous trait variation was found to be ubiquitous. Responses to moisture availability were generally similar within and between PFTs, but biophysical traits (LA, SLA and LDMC) of forbs and grasses responded differently from woody plants. SLA and LDMC responses to temperature were dominated by the prevalence of evergreen PFTs with thick, dense leaves at the warm end of the gradient. Nutrient (N, P and K) responses to climate gradients were generally similar within all PFTs. Area-based nutrients generally declined with moisture; Narea and Karea declined with temperature, but Parea increased with temperature. Although the adaptive nature of many of these trait-climate relationships is understood qualitatively, a key challenge for modelling is to predict them quantitatively. Models must take into account that community-level responses to climatic gradients can be influenced by shifts in PFT composition, such as the replacement of deciduous by evergreen trees, which may run either parallel or counter to trait variation within PFTs. The importance of PFT shifts varies among traits, being important for biophysical traits but less so for physiological and chemical traits. Finally, models should take account of the diversity of trait values that is found in all sites and PFTs, representing the "pool" of variation that is locally available for the natural adaptation of ecosystem function to environmental change.

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